Print calibration

1. A method for configuring a printing system comprising: obtaining data indicative of a relationship between colorimetry and deposition of printing colorant for a plurality of print elements of the printing system; determining a reference print element from the plurality of print elements of the printing system based on said data; determining calibration data for at least one selected print element in the plurality of print elements based on said data, the calibration data calibrating deposition of printing colorant for the at least one selected print element with reference to the reference print element; calibrating the at least one selected print element using the determined calibration data, the at least one selected print element calibrated against the reference print element; and printing an image, by the print elements, including by the reference print elements and by the calibrated at least one selected print element.

2. The method of claim 1 , wherein the relationship between colorimetry and deposition of printing colorant comprises a relationship between a lightness metric and printing colorant drop density.

3. The method of claim 1 , wherein determining a reference print element comprises: determining a set of colorimetry-deposition metrics, each colorimetry-deposition metric being for a given set of colorimetric values and being associated with a particular print element in the plurality of print elements; determining a print element based on the set of set of colorimetric-deposition metrics.

4. The method of claim 1 , wherein determining calibration data comprises: determining a printing colorant density ratio for the at least one selected print element, the printing colorant density ratio representing, for a given colorimetric value, a relationship between deposition of printing colorant for the at least one selected print element and deposition of printing colorant for the reference print element.

5. The method of claim 1 , wherein obtaining data indicative of a relationship between colorimetry and deposition of printing colorant comprises, for one or more given print elements in the plurality of print elements: printing a test sample with the given print element, the test sample comprising a range of printing colorant densities; and measuring the colorimetry of the test sample to determine the relationship between colorimetry and deposition of printing colorant for the given print element.

6. The method of claim 1 , wherein: the relationship between colorimetry and deposition of printing colorant comprises a relationship between an L* metric in an L*a*b* color space and printing colorant drop density, determining a reference print element comprises: for a set of L* metric values, determining associated printing colorant drop density values for each print element in the plurality of print elements; and determining a reference print element as a print element with a lowest printing colorant drop density value for one or more of the set of L* metric values.

7. The method of claim 6 , wherein determining calibration data comprises, for one or more given print elements in the plurality of print elements: determining at least one calibration factor for the given print element, each calibration factor being based on, for a given L* metric value, a ratio of the printing colorant density value for the given print element and the printing colorant density value for the reference print element.

8. A non-transitory computer-readable medium comprising a program, which when executed by a processing system, causes the processing system: use calibration data to determine for a selected print element, an output printing colorant deposition value for a given colorimetry, the output printing colorant deposition value being determined as a function of a relationship between colorimetry and deposition of printing colorant for a reference print element; calibrate the selected print element using the determined output printing colorant deposition value, the selected print element calibrated against the reference print element; and print an image, by a plurality of print elements including the reference print element and the calibrated selected print element.